


the only one left to save

by Anxiety_Basket



Category: Undertale (Video Game)
Genre: Bad Frisk, F/F, Frisk is v nosy, Good Chara, LGBTQ+ Ships, M/M, Other, W. D. Gaster Is Not Related to Papyrus and Sans, frisk is tryna make things right but is v miguided
Language: English
Status: In-Progress
Published: 2020-08-05
Updated: 2021-01-19
Packaged: 2021-03-05 21:15:39
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 6
Words: 3,868
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/25731967
Author URL: https://archiveofourown.org/users/Anxiety_Basket/pseuds/Anxiety_Basket
Summary: Frisk notices that Sans seems to be the only monster who they haven't helped and decides to try change that.
Relationships: Alphys & Frisk (Undertale), Alphys/Undyne (Undertale), Frisk & Papyrus (Undertale), Frisk & Sans (Undertale), Minor or Background Relationship(s), Papyrus & Sans (Undertale), W. D. Gaster/Sans
Comments: 13
Kudos: 57





	1. happy

They were a child. That's what everyone had said as they apologized. They shouldn't have had to go through that. Shouldn't have had to be the one to save the monsters.

They didn't care.

They just wanted their friends to be happy. If that took millions of Resets and True Resets, than so be it.

They'd befriended Chara, and it seemed almost too easy after what the dead child had done.

It was Asriel- Flowey, they corrected. He was the problem. He refused time and time again. Reset after Reset. He just didn't believe he deserved Mercy. Much less theirs. What was probably the equivalent to years had passed as they Reset. To get the flower monster to agree. To finally understand.

That was the timeline they were in now. Everyone they knew was as happy as could be. They were finally happy, too. Away from their shitshow of an orphanage.

They had a family.

A real, loving family.

Happy

It was a feeling they hadn't had in a long time.

They thought they'd saved everyone.

Oh, how wrong they were.


	2. determined for answers

**Summary for the Chapter:**

> Frisk goes snooping more thoroughly through Sans' lab.

Frisk had noticed the disappearances of one of their friends becoming more and more frequent.

They'd asked, he'd lied.

Down to the underground, they figured. That stupid machine that got more advanced with each reset. As if new information had been discovered. The only room unaffected by resets.

Impossible. They'd thought, blamed it on their imagination. 

_Beware the man who speaks in hands. ___

____

____

That was the message, the warning, they'd gotten stepping off the River Person's boat. Frisk had obviously heard it before. They'd heard it all millions of times. But they'd never figured out what it meant. Who was the man they mentioned?

They pondered that as they walked through the abandoned town of Snowdin. 

Reaching the old house of the wacky skeleton brothers, Frisk slipped (literally, the ground was solid ice,rather than the usual snow) around to the back door...? Basement? Whatever it was.

They still had the key. So they entered the strange lab-like area of the house.

Frisk frowned when they saw no sign of the lazy skeleton. Even if he wasn't here, maybe they could still gather some sort of clue as to why the skeleton was so determined to make the machine work.

But it was the same as usual, the photo of three people, scrawled on the back the words 'don't forget,' sans smiling a real smile surrounded by other monsters.

They were about to leave when they realized the third draw, usually locked, was slightly open. Sans must have forgotten to close it.

They opened it.

It was a photo album. Filled with the Sans they had never known. The scientist Sans. The happy Sans. Each photo was either taken of Sans when he wasn't expecting it, him and a different skeleton smiling brightly at the camera or at each other. Papyrus, Frisk realised, was featured in a few photos, except these must have been takes years ago. Because Papyrus was shorter than Sans.

They looked like they were a happy family. Frisk felt kind of jealous of the three skeletons.

Alphys was also featured in one or two potoigraphs, seen in one as she and Sans watched some anime on the computer. Sans looked confused at what was happening but Alphys looked happier than Frisk had ever seen her.

The third Skeleton, W.D Gaster as a name tag in one of the photographs says, was unfamiliar. Frisk never seen them in the underground. No one had mentioned the scientist. Well, they assumed he was a scientist, considering he wore a lab coat in many of the photos.

Why did he mean so much to Sans?

Frisk wanted to know. Needed to know how to make Sans happy.

After all the things they'd let 'Chara' do to the underground (they'd settled for blaming the deceased child, refusing any responsibility), Sans deserved at least this bit of happiness.

Frisk stuffed the photo album in their inventory, and left the small room. 

They'd resolved to ask Sans about it later, since they were staying at the skeletons house anyway.

They hurried back to the River Person and out of the underground.


	3. avoiding answers

**Summary for the Chapter:**

> Frisk doesn't get the answers they were looking for, they are _not _happy.__

Silence rang through the room.

They'd only asked a single question. So what was with this reaction...?

As the silence droned on, Frisk began to get impatient.

"Who is Gaster?" They asked for the second time.

Papyrus, being the first to find his words, responded to the human.

"Well, you see, Human, I'm not sure where you heard of Gaster, but, he's... An old friend?" Even Papyrus looked doubtful at his own words. "I think he was, anyway. I... Can't remember much of him. I know I met him... I was around him a lot... I just... Don't remember clearly."

Papyrus sounding so unsure put Frisk on edge. Papyrus was always _over _confident when he spoke. It was strange, seeing him doubt himself so much.__

"Jeez kid, where'd you even _hear _that name."__

__"Well..." They hesitated. "I... Um... I went snooping, and, well, found this." They said, placing the photo album on the table. "He had a name tag... I'm sorry, I shouldn't have gone snooping." They added, seeing Sans' look of horror._ _

__Sans slowly slid the album to himself and opened it, chocking back a mix between a sob and a laugh._ _

__"Hey, Pap, this was your ninth birthday, remember?" He said, showing him a picture._ _

__The picture was in black and white, Papyrus sat in front of a cake, looking fed up of everything. Sans stood next to him, looking like he was laughing hysterically. Surprisingly, Undyne was on Papyrus' other side, frowning at whatever the person behind the camera had said._ _

__"Ugh. Instead of saying "smile" he made a pun. Only Sans found it funny." He complained_ _

__"It was a good day, though." Sans chimed in, obviously amused._ _

__"I guess..." Papyrus huffed._ _

__"Hey, your lucky I let Undyne in the house, considering I'd just met her." Sans smiled.__

__Frisk knew Sans was avoiding the question but decided to drop it for the time being. They'd ask after school tomorrow. Sans was bound to tell them eventually. And if not, they'd ask other monsters._ _

They already had Undyne, as a start. She was in the picture, maybe she knew something. If not, maybe Alphys knew the scientist, it was worth a try at least.

Frisk quickly finished their dinner and went up to the guest room of the skeletons new house.

**Notes for the Chapter:**

> OK, so, a bit of info on my AU.  
> 1: Sans and Flowey are the only monsters to remember resets, Frisk and Chara being the only humans.  
> 2: Chara is a good guy, they didn't cause the genocide, Frisk just blames them and refuses all responsibility  
> 3: Frisk and Chara are gender neutral, as they are in the game.  
> 3: Gaster, Sans and Papyrus are not related, in case you didn't read the tag.  
> 4: Papyrus, while not remembering the resets does remember a bit about Gaster. So does Alphys. Their memories aren't as Vivid as Sans' but they are the only others to remember him.  
> 5: Sans is depressed, but is not suicidal. He doesn't hurt himself in anyway that isn't an accident (like slipping on ice, or tripping over a shoe lace) because he only has 1hp and that could kill him.  
> 6: There is no Player. Every decision was made of Frisk's own free will, they just refuse responsibility for their actions.


	4. Alphys

**Summary for the Chapter:**

> Undyne makes a v brief appearance, Alphys is literally my baby fight me.  
> Alphys takes up majority of this chapter.

School had been the same as usual. Boring. They'd much rather be investigating the mystery that is Sans the skeleton. He could probably teach them more science than this teacher, anyway.

Frisk waited by the gate of the school, Papyrus was picking them up today. When Papyrus finally arrived in his red convertible, Frisk climbed into,the backseat.

The drive back to,the skeleton's house was awkward, the tension from the previous night still lingering between them.

When they arrived at the house Frisk decided they probably wouldn't get anything out of Sans or Papyrus. They thought for a while and decided Alphys was their next best clue, as she'd been in the photos with Science Sans.

They finished all their homework and told Sans (because Papyrus was out getting ingredients for more spaghetti) they were going out a for a while. Sans responded with an "ok. i'll text you when dinners almost done."

Frisk quickly left the house, sneaking the photo album they'd discovered into their inventory. Alphys and Undyne only lived down the road, as a lot of monsters clustered together in places. Which meant there were less humans. And any humans that were there were cool with the monsters. _The nice ones _Frisk had decided.__

Frisk quickened their pace, they wanted as many answers as they could get before returning for dinner. When they arrived at Alphys' house they took a deep breath, calming their nerves and planning out what to say in their head, before finally knocking on the door.

Unsurprisingly, it was Undyne who answered, her being the more sociable of the couple.

"Oh, hey punk. What's up?" She asked, smiling.

"Well... Uh... You see..." Frisk fumbled over their words as the frustration piled up. They took a deep breath. "I need to talk to Alphys, please."

"Oh. Is that it? Come on in. I'm heading out for a bit anyway. Do what you gotta do." She grinned before calling into the house "HEY! ALPHYS, IM HEADING OUT. FRISK'S HERE TO SEE YOU! DON'T DESTROY THE HOUSE WITHOUT ME!" 

"W-we won't!" Alphys called back feebly. 

Undyne let Frisk into the house before exiting and closing the door behind her. They walked to the living room, where they knew Alphys was most likely to be.

"H-hey Frisk!" She greeted. "Undyne said you wanted to see me?"

Frisk nodded and Alphys gulped.

She was still slightly hung up on past mistakes, but she was a lot better than she was back underground!

"Do... Do you know anyone by the name of 'Gaster'?" Frisk got straight to the point.

"G-Gaster? I... I don't know... The name... Sounds familiar? I think he was a scientist...? We worked together....?" She clutched her head slightly before sighing, "sorry, Frisk, I'm... Sure I recognise the name but that's bout it."

"If you don't mind, do you know where exactly you remember it from?"

She thought for a minute. "Oh!" She exclaimed before going over to the bookcase. She scanned the rows of books and research before stopping at one.

"This. I've... I've never been able to read it."

"Huh?" How could she not read it? "What do you mean?"

"Here, see for yourself." She handed Frisk the papers.

Frisk's eyes widened. The writing was in complete different language. Wait... No... Was that a font? There was some writing like that in the photo album, too. On a few pictures that Gaster must have taken and added the captions.

Who was W.D. Gaster and why did he use it? Wait... W.D?

"It looks like... Hey, could this be WingDings?" They asked.

Alphys paused and looked at it again, smacking herself on the forehead. "How did I not notice that?" She sighed. "But no one speakers WingDings anymore..."

Frisk handed the papers back to Alphys and pulled the album out of there inventory. They flipped through at a slower pace and when the got to the end they were surprised.

"Someone does still speak it..!"

"What?"

In the very back of the album, was the only coloured photo. It had Frisk and their friends, Tories, Sans and Papyrus, Undyne and Alphys, Asgore and even Mettaton. _When was this taken!? _they thought. Underneath the picture was some words scrawled carelessly in Wingdings.__

__"Who?" Alphys asked "Who do you think wrote it?"_ _

__"Sans. I found the photo album in some lab thing under his and Paps old house. I only found it last night and didn't have chance to properly go through it." They rambled. "But he and Papyrus wouldn't tell me anything about Gaster. Papyrus doesn't really remember and Sans always changed the subject."_ _

__"Well, maybe you brought it up too forcefully. Maybe he has bad memories of Gaster he wants to forget?" Alphys suggested._ _

__"Maybe... Thanks for the help, Alphys. I should get going now anyway." They said walking to the front door. "Bye!" Frisk waved._ _

__"See ya!" Alphys waved back,closing her front door._ _

__Frisk sighed and started on their way back to,the skeletons house. They'd received no texts from Sans, so he was either fast asleep on the couch or Papyrus isn't close to finished yet._ _

__They walked silently along the road, thinkingly all the while._ _

___**D O N ' T Y O U K N O W I T S R U D E T O T A L K A B O U T S O M E O N E W H O ' S L I S T E N I N G** _ _ _

**Notes for the Chapter:**

> So, this took a while since my head was in a bad place for a while and I lost all motivation but here we go. The 4th chapter. Where absolutely nothing interesting happens lmao.
> 
> I'm finally getting used to Ao3 tho


	5. I Am So So Sorry

**Summary for the Chapter:**

> An Apology And An Explanation (Skippable)

Okay, I am so sorry at how long a delay there has been. Things have been pretty hectic lately. 

So, luckily my area is only a level one so I'm not in too much danger from Covid-19.  
However, a few weeks ago we did get tested, luckily negative, because we'd had a symptom or two, but I get sick this time every year so no biggie.  
I have had my GCSE Mocks not too long ago, and the Covid test meant I had to catch up on 2 of them, which sucked.  
Apparently other schools in my area aren't even doing mocks so... Yay me.

But anyway. I have been so swamped with studying for those exams and doing schoolwork in general, y'know, tryna catch up a whole 6 months worth of work, that i haven't had much time to write.  
That being said, I HAD a whole ass chapter ready to be posted but apparently I forgot and AO3, the scumbag it is, deleted it >:( so now it'll take even longer than before.

I am so sorry for the delay.  
Please forgive me bc I also have like 5 hw assignments due the 2nd of November that I'm gonna do all of tomorrow   
Its mostly on a website called seneca so i can just blast through it tho lmao.  
And the booklets we were given have answers in the back and since I wasn't here for that ig ill cheat. I was supposed to copy someone's work but the pictures i took came out unreadable whoops.

Anyway, enough about my life. I hope you are all okay.  
Goodbye, and stay safe :)


	6. voices

**Summary for the Chapter:**

> This chapter dives a bit deeper into characters that aren't just Frisk (Sans actually hasn't come up as much as I'd have liked him to. Paps too) We get to see a "new" development of Papyrus, this is where is stops being so "canon" and more "fanon/headcanon" based. This story is set after Frisk has done a looootttt of resets, and I decided that I wanted to use what I think about the skele-bros, and not just the tiny part we're told (or hinted at) in-game. Remember: every playthrough of the game is diffetent, you can see the gaster followers and his door or you dont. There's the easter-egg phone calls, from both Sans and Alphys.

**Notes for the Chapter:**

> Pls let me know any typos so I can correct them! I rushed the end cuz y'all have been a waiting a while. On the bright side, this is now the chapter with the most words (bc I can't write long chapters so they're all super short and take millions of years to come out and I am so sorry)  
> This story is difficult to write :(

**Don't you know its rude to talk about someone who's listening?**

Frisk froze, turning their head side to side as quick as possible, looking for the owner of the voice.

They couldn't see anyone. The street was completely devoid of monsters and humans.

 _Who said that??_ Frisk thought.

They gulped and began to walk again, deciding to quicken their pace. The sooner they got back to the skeletons house, they sooner they were safe. Papyrus would protect them, Sans would, well, Frisk was sure he'd do something he had to, right? He may be lazy, but Frisk was sure he'd protect them.

They knew of his... abilities. They'd -No, Chara, not them- had done so many genocides that they knew each and everyone of Sans' attacks. It was instinct to dodge at this point, but they wouldn't need to, wouldn't in general, they'd promised no more resets, and Frisk intended to keep that promise, no matter how bored they got.

Boredom. 

Did that really make them reset all those times? Did it justify all the times they'd made their friends (Were they really friends at this point?) miserable? What about Sans? Or Flowey? And any other monster unfortunate enough to remember the resets? They'd seen, _experienced_ , awful, cruel, vile things, all because of Frisk's boredom? Their curiosity? 

NO!

 _No_. That isn't what happened. Frisk knew it wasn't their fault. They hadn't been in control. Chara had. Hadn't they? Did they really though...? If they were truly evil, would they have just shrugged and rolled their eyes when Frisk told them to stop? 

Frisk shook the thought out of their head, they couldn't afford to think about that right now. And hopefully they never would. They did not want to, thank-you-very-much.

Frisk shook their head again, and ended up walking face first into the door of the skeleton's house. 

"Ow" They muttered. It may not be as hurtful as monster attacks, but even the weakest monsters they'd faced (In pacifist, genocide and neutral) had stronger attacks then what a door could do. The door didn't even take .1 of their total HP (Only 20hp, the amount it reset to every time) It wasn't as high as someone like Papyrus, or Undyne (She had way too much HP), but not as low as Sans and his measly 1hp, one nasty fall and he could dust.

*1 Attack, 1 Defence, 1HP.

*The easiest enemy.

At least, they both had assumed. But his magic was strong. Stronger than Papyrus, Undyne, hell, Frisk assumed by this point he was stronger than the King of monsters, Asgore. Not only that, but his magic was different, unique. And the only other people who seemed to know were Papyrus and Asgore.

Not his boss. Not his best friend. No.

The king. And the baby brother he just wanted to protect. The same brother who he kept so many secrets from. It was difficult to believe he'd tell Papyrus such a big secret. But then again, Frisk occasionally forgot just how skilled he was. How strong, how smart, he was.

He and Alphys had been friends before Frisk even fell, yet no one else knew that. They'd seen the pictures in the album, so Papyrus must have known at the least, right? Apparently he knew as little on the situation as they did, because he'd questioned their unlikely friendship, too. Were they really friends though? Maybe it was one of those work-only friendships their human dad had had with his co-workers, the kind where you got along enough to work together, but never interacted outside of work.

Sure, she and Undyne were friends, but everyone had known that much. (Except them on their first run, but that's because they had more important things to worry about back then. Like surviving, helping.) And Undyne hates going to Hotland, she'd made that extremely clear to everyone around her.

Frisk sighed. All the thinking they'd done this day (yes, that included the school Toriel insisted they go to, despite how much they complained) was scrambling their brain. It was getting difficult to keep their thoughts straight, by now even timelines were getting mixed up. 

Maybe they should listen to Toriel and start writing things down to get it out of their head. They'd have to hide it really well, and maybe get one of those ones where you need a key, because they couldn't let something written about the resets and timelines be found and read by a random monster who didn't know. 

They finally (it felt like they'd been stood in front of the door, thinking for hours. But in reality it had only been a minute, maybe two that had passed.) opened they door and stepped through, into the warmth of the house.

"I'm back." They called.

They were greeted with silence.

"S-Sans? Pap-Papyrus? If this is a joke you can come out now" Nothing. Hearing that strange voice must have put them more on edge than they though. The skeletons would be fine. Sans was strong, Undyne said Papyrus was strong (although Frisk was yet to see his full abilities) so they would be fine. Hell, they probably weren't in any danger to begin with. Sans probably left to go get Papyrus, who probably got lost (He got lost a lot, he sometimes forgets they aren't in Snowdin anymore)

Frisk shook away bad thoughts (again) and decided they'd be better doing something productive, like what? Sleep. They'd wake up and the brothers would be back, and everything would be fine 

Frisk fell asleep almost instantly.

\---

"come on, pap, the kid'll be fine, they probably assumed you got lost again and i went to get you." Sans shrugged.

Papyrus had gotten home only a few minutes after Frisk left, and Sans decided it was the perfect time to drag his brother to their "Private Place" to talk about the stuff Frisk was brining up

"besides, the kid set us free from the underground, they're strong, they'll be okay"

"I... I suppose you are right, brother. Human Frisk is very strong indeed. They did manage to beat... everything... even you"

"pap. You know i'm nowhere near as strong as you, but you... you're a lot nice than i am. We've been through this, you don't have the intent, you trust people, i... i don't. in reality, if you really really needed to, you could beat me, and undyne and even... even that thing."

A thing, that's what he referred to Frisk as when they were alone. Just the two of them. Just the goofy sekle-brothers who knew a lot more than they'd let on. No one questioned them, Sans wouldn't talk and Papyrus, well, he was really good at being fake confused. By this point it was hard for even his brother to tell when he was fake and when he was genuine, but, ultimately, he always could. Just how Papyrus can tell when his brother's lying.

Neither calls the other out. Ever.

They had to much to lose.

Sans' machine had always intrigued Papyrus, so much so that Sans' little room (They don't call it a lab, the word brings back bittersweet memories) had become their safe-heaven, a place to talk amongst themselves. A place of privacy. And even if Frisk did reset (Papyrus really, really hoped they wouldn't break their promise. He didn't know how much more he could take of this cycle. He didn't know how much his brother could handle. 

Sans had told him himself, one timeline, that Papyrus was the reason he was still around, still alive, still able to get out of bed every morning (Papyrus' heart broke at the thought of his brother being so hopeless, monsters needed hope to live, after all) Papyrus understood. If either of them were gone for good, the other wouldn't survive very long.) if Frisk did reset, he and his brother would at least be together. At least they had each other, they wouldn't have to go through it alone.

Sans would wake up screaming, again, and Papyrus would look out his window and see the snow covered town before going to comfort his older brother. They'd fall back into their usual routine, a bit less hopeful, but Papyrus would still (In Sans' eyes he always would) burn brighter than the stupid sun could ever hope to.

Papyrus would watch in awe as Sans delicately handled his tools, fixing the machine and admiring how fast he was at typing line after line of codes into a computer. Papyrus would compliment him (They were always genuine. He truly thought his brother was amazing at these thing) and Sans would shrug, and say something along the lines of "not as cool as you, bro" or even the less frequent "thanks, g taught me, me and al learnt from the best, after all." A small smile crossing his face as he stared Papyrus dead in the eyes (Papyrus won't admit it out loud but those times made him happy, showed him his brother was living, not just surviving)

"Sans?"

"yeah, bro?"

"I'm sure we'll get it this time."

"yeah? me too, papy."

They both knew it most likely wouldn't happy, they said it each reset. But they also both knew it kept their hopes up just that tiny bit higher, making sure neither would turn to dust due to hopelessness. It wasn't the words that gave them the hope, it was the support Sans felt, the way Papyrus showed he believed in his brother wholeheartedly. They were never really alone, they always had the other to rely on.

**Notes for the Chapter:**

> What did y'all think?? This kind of Papyrus was reaalllyyyy difficult to get just right (I retyped the same sentence at least three times at some point) he's not a perfect boi just yet, though none of the characters are yet.
> 
> But hey! Frisk had a bit of self-reflection! Even the tiniest bit counts for them.
> 
> I love the Skele-bro's and their relationship is adorable. Pap being able to remember resets actually has more evidence than people think! When you enter Sans' room and he comes in to turn the light on he says something along the lines of: "Did Sans prank you through time and space? I hate it when he does that." This line really gave me the impression he knew about Sans and his strange abilities (shortcuts/teleporting) and I decided to run with the whole "He knows who Gaster is and what resets/timeline are he's just a great actor." because... Idk I just thought "OOOooohhh more secrets for Frisk to unravel"
> 
> N E Ways. I've talked enough, sorry this chap took so long
> 
> Bye bye!

**Author's Note:**

> I know the first chapter is short, its just an introduction chapter. I wanted to experiment a bit with my writing and I love the Sanster ship.


End file.
